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Rutherford category IIb acute limb ischemia — ABIM Board MCQ

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HardVascular DiseaseRutherford category IIb acute limb ischemiaABIM Board

A 69-year-old man presents with 4 hours of abrupt, severe left leg pain. He has no history of claudication or lower-extremity revascularization. Six weeks ago, he had a small nonhemorrhagic ischemic stroke with complete neurologic recovery. His medications are aspirin, atorvastatin, and amlodipine. Temperature is 98.4°F (36.9°C), blood pressure is 146/84 mm Hg, and pulse is irregularly irregular at 112/min. ECG shows previously unrecognized atrial fibrillation. The left leg is pale and cool below the knee. The femoral pulse is palpable, but popliteal and pedal pulses are absent. Pinprick sensation is reduced over the entire foot and distal calf, and ankle dorsiflexion strength is 3/5. Arterial Doppler signals are absent below the femoral artery, but venous Doppler signals remain audible. The right leg is normal. Platelet count, INR, aPTT, and creatinine are normal. Vascular surgery and an operating room are immediately available. Which of the following is the most appropriate immediate management?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — Start unfractionated heparin and proceed immediately to operative embolectomy

Explanation lettering: C = shown as A · A = shown as B · D = shown as C · B = shown as D

This patient has acute limb ischemia with sensory loss extending beyond the toes, mild motor weakness, absent arterial Doppler signals, and preserved venous signals—Rutherford category IIb, an immediately threatened but salvageable limb. He requires systemic unfractionated heparin and emergent revascularization. The abrupt presentation, newly recognized atrial fibrillation, lack of preceding claudication, and palpable femoral pulse suggest an embolic occlusion amenable to operative embolectomy. A is incorrect because category IIb ischemia is diagnosed clinically and revascularization should not be delayed for CT angiography, particularly without a complicated history of prior revascularization. B is initially attractive because catheter-directed thrombolysis is a revascularization option for selected acute limb ischemia; however, motor weakness demands rapid reperfusion, and an ischemic stroke within 2 months is a contraindication to thrombolytic therapy. D is inadequate because anticoagulation prevents propagation but does not promptly restore perfusion to an immediately threatened limb. E is reserved for irreversible category III ischemia, characterized by complete anesthesia, paralysis, and absent arterial and venous Doppler signals. Preserved venous signals and incomplete neurologic deficits indicate that this limb remains salvageable.

Reference: 2024 ACC/AHA Multisociety Guideline for the Management of Lower Extremity Peripheral Artery Disease (May 14, 2024) — https://professional.heart.org/en/-/media/PHD-Files-2/Science-News/2/2024/2024-PAD-guideline-slide-set.pdf 2024 ACC/AHA Multisociety Guideline for the Management of Lower Extremity Peripheral Artery Disease (May 14, 2024) — https://professional.heart.org/en/-/media/PHD-Files-2/Science-News/2/2024/2024-PAD-guideline-slide-set.pdf Catheter-Directed Thrombolysis for Acute Limb Ischemia (2006) — https://pmc.ncbi.nlm.nih.gov/articles/PMC3036379/